Method for processing target object

ABSTRACT

In a method according to an embodiment, before etching a target layer of a wafer, a main surface of the target layer is divided into a plurality of areas. A difference value between a groove width of a mask and a reference value of the groove width is calculated for each of the plurality of areas, a temperature of the target layer is adjusted by using correspondence data indicating correspondence between a temperature of the target layer and a film thickness of a formed film. Then, a film is formed on the mask for each atom layer, and a film having a film thickness corresponding to the difference value is formed on the mask to correct the groove width in each of the plurality of areas to the reference value.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.16/135,178, filed on Sep. 19, 2018, which is a Continuation-in-part ofInternational Application No. PCT/JP2017/019024, filed on May 22, 2017,which claims priority from Japanese Patent Application No. 2016-104414,filed on May 25, 2016, all of which are incorporated herein in theirentireties by reference.

TECHNICAL FIELD

An embodiment of the present disclosure relates to a method forprocessing a target object.

BACKGROUND

In a manufacturing process of an electronic device such as asemiconductor device, a mask is formed on a target layer, and etching isperformed for transferring a pattern of the mask to the target layer. Asthe mask, a resist mask is generally used. The resist mask is formed bya photolithography technology. Accordingly, a critical dimension of apattern formed on a layer to be etched is influenced by, for example, aresolution limit of the resist mask formed by the photolithographytechnology and a pattern density. However, recently, with the highintegration of electronic devices, it is required to form a patternhaving dimensions smaller than the resolution limit of the resist mask.Therefore, as described in Japanese Patent Application Laid-Open No.2004-080033, there has been suggested a technology for decreasing awidth of an opening provided by a resist mask by forming a silicon oxidefilm on the resist mask and adjusting the dimensions of the resist mask.

In a method of forming a micro-pattern disclosed in Japanese PatentApplication Laid-Open No. 2004-080033, a photoresist pattern is formedon a material film on which a micro pattern is to be formed, and then asilicon oxide film is deposited on the material film, but the siliconoxide film needs to be conformally thinly formed without damaging thephotoresist pattern thereunder. Then, dry etching is also performed on alower film, but at an initial stage, a spacer is formed on a lateralwall of the photoresist pattern and subsequently a polymer film isformed on the photoresist pattern.

SUMMARY

In an aspect, a method for processing a target object is provided. Themethod includes: a first step of adjusting a width of a mask pattern ofa mask provided on a main surface of a target layer included in thetarget object, the main surface being divided into a plurality of areas;and a second step of etching the target layer by using the mask afterthe first step. The first step includes: a third step of measuring thewidth of the mask pattern for each of the plurality of areas of the mainsurface, a fourth step of calculating a positive difference valueobtained by subtracting a reference value of the width of the maskpattern from the width of the mask pattern measured in the third stepfor each of the plurality of areas of the main surface after the thirdstep; and a fifth step of forming a film having a thickness of thepositive difference value of each of the plurality of areas of the mainsurface calculated in the fourth step on a surface of the mask of thetarget object introduced into a processing container of a plasmaprocessing device after the fourth step. The fifth step includes: asixth step of supplying first gas into the processing container; aseventh step of purging an inside of the processing container after thesixth step; an eighth step of generating plasma of second gas within theprocessing container after the seventh step; a ninth step of purging theinside of the processing container after the eighth step; and repeatingthe sixth step to ninth step thereby forming a film on a surface of themask. In the fifth step, a temperature of the target layer of the targetobject introduced into the processing container is adjusted for each ofthe plurality of areas by using pre-acquired correspondence dataindicating correspondence between a temperature of the target layer anda film thickness of a film deposited on the surface of the mask on thetarget layer, and a film thickness corresponding to the difference valuecalculated for each of the plurality of areas in the fourth step; and aprocessing time required in the sixth step falls within a time periodduring which the film thickness of the film deposited on the surface ofthe mask on the target layer increases or decreases according to atemperature of the target layer in the sixth step.

The foregoing summary is illustrative only and is not intended to be inany way limiting. In addition to the illustrative aspects, embodiments,and features described above, further aspects, embodiments, and featureswill become apparent by reference to the drawings and the followingdetailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart illustrating a method for processing a targetobject according to an embodiment.

FIG. 2 is a cross-sectional view illustrating a target object to whichthe method illustrated in FIG. 1 is applied.

FIG. 3 is a diagram illustrating an example of a processing system,which is usable for carrying out the method illustrated in FIG. 1.

FIG. 4 is a diagram illustrating an example of a plasma processingdevice, which may include the processing system illustrated in FIG. 3.

FIG. 5 is a flowchart illustrating an example of a step of adjusting agroove width of a pattern before etching, which is a step that may beincluded in the method illustrated in FIG. 1.

FIG. 6A is a cross-sectional view illustrating a state of an targetobject before the steps illustrated in FIG. 5 is performed, and FIG. 6Bis a cross-sectional view illustrating a state of the target objectafter the steps illustrated in FIG. 5 is performed.

FIG. 7 is a diagram schematically illustrating some of a plurality ofdivided areas of a main surface of a target object in the method forprocessing a target object according to an embodiment as an example.

FIG. 8 is a flowchart illustrating an example of a step of adjusting agroove width of a pattern, which is a part of the steps illustrated inFIG. 5.

FIG. 9 is a flowchart illustrating an example of a step of forming auniform film on a main surface of the target object, which may beincluded in the steps illustrated in FIG. 8.

FIG. 10A is a diagram schematically illustrating a state of a targetobject before the sequence illustrated in each of FIGS. 8 and 9 isexecuted, FIG. 10B is a diagram schematically illustrating a state ofthe target object during execution of the sequence illustrated in eachof FIGS. 8 and 9, and FIG. 10C is a diagram schematically illustrating astate of the target object after the sequence illustrated in each ofFIGS. 8 and 9 is executed.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawing, which form a part hereof. The illustrativeembodiments described in the detailed description, drawing, and claimsare not meant to be limiting. Other embodiments may be utilized, andother changes may be made, without departing from the spirit or scope ofthe subject matter presented here.

When a pattern having a smaller value than a resolution limit of aresist mask is formed, there is a demand for very precisely controllinga critical dimension (CD) of a groove of the pattern. When the patternis elaborate, an influence by a variation in the critical dimension isincreased. Accordingly, in forming a pattern on an target object, thereis a need for implementing a method of suppressing a variation in thehighly precise critical dimension in order to achieve theminiaturization with high integration.

In an aspect, a method for processing a target object is provided. Themethod includes: a first step of adjusting a width of a mask pattern ofa mask provided on a main surface of a target layer included in thetarget object, the main surface being divided into a plurality of areas;and a second step of etching the target layer by using the mask afterthe first step. The first step includes: a third step of measuring thewidth of the mask pattern for each of the plurality of areas of the mainsurface, a fourth step of calculating a positive difference valueobtained by subtracting a reference value of the width of the maskpattern from the width of the mask pattern measured in the third stepfor each of the plurality of areas of the main surface after the thirdstep; and a fifth step of forming a film having a thickness of thepositive difference value of each of the plurality of areas of the mainsurface calculated in the fourth step on a surface of the mask of thetarget object introduced into a processing container of a plasmaprocessing device after the fourth step. The fifth step includes: asixth step of supplying first gas into the processing container; aseventh step of purging an inside of the processing container after thesixth step; an eighth step of generating plasma of second gas within theprocessing container after the seventh step; a ninth step of purging theinside of the processing container after the eighth step; and repeatingthe sixth step to ninth step thereby forming a film on a surface of themask. In the fifth step, a temperature of the target layer of the targetobject introduced into the processing container is adjusted for each ofthe plurality of areas by using pre-acquired correspondence dataindicating correspondence between a temperature of the target layer anda film thickness of a film deposited on the surface of the mask on thetarget layer, and a film thickness corresponding to the difference valuecalculated for each of the plurality of areas in the fourth step; and aprocessing time required in the sixth step falls within a time periodduring which the film thickness of the film deposited on the surface ofthe mask on the target layer increases or decreases according to atemperature of the target layer in the sixth step.

In the method, before the second step of etching the target layer, thefirst step of adjusting the width of the mask pattern of the mask isperformed. In the first step, the main surface of the target layer isdivided into a plurality of areas, in the third and fourth steps, adifference value between the width of the mask pattern and the referencevalue of the width is calculated for each of the plurality of areas, andin the fifth step, a film having a film thickness corresponding to thedifference value is formed on the mask and the width of the mask patternin each of the plurality of areas is corrected to the reference value.In the fifth step, the film is very precisely formed in each atom layeron the mask by the same method as an atomic layer deposition (ALD)method by using the film forming processing in which the sixth step tothe ninth step are repeatedly executed. Since the film thickness of thefilm formed by the film forming processing is different according to atemperature of the target layer, in the tenth step, the temperature ofthe target layer is adjusted so that the temperature of the target layerbecomes a temperature required for forming a film having the filmthickness corresponding to the difference value calculated in the fourthstep for each of the plurality of areas by using correspondence dataindicating correspondence between a temperature of the target layer anda film thickness of a formed film. As described above, before theetching performed in the second step, a film thickness corresponding toa correction amount of the mask pattern is determined for each of theplurality of areas of the main surface of the target layer, atemperature of the target layer required for forming the film thicknessis determined by using the correspondence data, and the same filmforming processing as the ALD method is performed in the state where thetemperature of the target layer is adjusted to the temperaturedetermined for each of the plurality of areas, so that the variation ofthe pattern of the mask may be precisely and sufficiently suppressed foreach of the plurality of areas of the main surface of the target layer.

In an embodiment, the temperature of the target layer is adjusted basedon the correspondence data for each of the plurality of areas such thata temperature of each of the plurality of areas in the target layer ofthe target object introduced into the processing container becomes atemperature corresponding to a film thickness of the difference valuecalculated for each of the plurality of areas in the fourth step.

In an embodiment, in the fifth step the film on the surface of the maskis conformally formed regardless of the plurality of areas, thetemperature of the target layer is adjusted based on the correspondencedata for each of the plurality of areas such that a temperature of eachof the plurality of areas in the target layer of the target objectintroduced into the processing container becomes a temperaturecorresponding to a value obtained by subtracting a film thickness of thefilm conformally formed from a film thickness of the difference valuecalculated for each of the plurality of areas, and adjusting thetemperature of the layer based on the correspondence data for each ofthe plurality of areas is performed before adjusting the temperature ofthe layer using the pre-acquired correspondence data or after the filmforming processing. As described above, for a common film thicknessamong the film thicknesses of the plural areas, it is possible topartially form the film without adjusting a temperature of the targetlayer performed on each of the plurality of areas.

In an embodiment, the first step includes re-executing the third stepand the fourth step after execution of the fifth step, and re-executingthe fifth step when the re-execution of the third step and the fourthstep does not cause a difference value calculated in the fourth step tosatisfy a preset reference range. As described above, after the film isformed by the fifth step, a difference value of the width of the maskpattern is calculated again, it is determined whether the differencevalue is within a reference range, and the forming of the film isperformed again when the difference value is not within the referencerange, so that the variation of the width of the mask pattern may befurther sufficiently suppressed.

In an embodiment, the first gas may include an aminosilane-based gas,and the second gas may include a gas containing oxygen atoms and carbonatoms.

In an embodiment, aminosilane-based gas of the first gas may includeaminosilane having one to three silicon atoms. The aminosilane-based gasof the first gas may include aminosilane having one to three aminogroups. As described above, as the aminosilane-based gas of the firstgas, aminosilane having one to three silicon atoms may be used. Further,as the aminosilane-based gas of the first gas, aminosilane having one tothree amino groups may be used.

In another aspect, a method for processing a target object is provided.The method includes: measuring a width of a mask pattern of a maskprovided on a surface of a target layer included in a target object foreach of a plurality of areas formed on the surface of the target layer;calculating a positive difference value obtained by substracting apredetermined reference value from the measured width of the maskpattern for each of the plurality of areas; adjusting a temperature ofthe target layer for each of the plurality of areas such that a filmhaving a film thickness corresponding to the difference value is formedby using pre-acquired correspondence data indicating correspondencebetween a temperature of the target layer and a film thickness of a filmdeposited on the surface of the mask on the target layer, and thedifference value calculated for each of the plurality of areas; andforming a film having the film thickness of the difference value foreach of the plurality of areas on the surface of the mask of the targetobject by using an atomic layer deposition, after the adjusting.

In the embodiment, the forming may be performed by repeatedly executinga sequence including: supplying a first gas into a processing container;purging an inside of the processing container; and generating plasma ofa second gas within the processing container.

In the embodiment, a time for supplying the first gas may fall within atime period during which the film thickness of the film deposited on thesurface of the mask increases or decreases according to an increase ordecrease in temperature of the target layer.

In the embodiment, the method further includes: measuring a width of themask pattern of the mask formed with the film after the forming for eachof the plurality of areas; and determining whether or not re-adjustmentof the width is required.

In the embodiment, the method further includes: etching the target layerusing the mask having a pattern width adjusted by the forming.

In the embodiment, the adjusting of the temperature, the forming, andthe etching are performed in a processing container without unloadingthe target object.

In yet another aspect, a method for processing a target object isprovided. The method includes: a first step of adjusting a width of apattern of a first mask provided on a surface of a first film of atarget layer of a target object; a second step of etching the first filmusing the first mask after the first step to form a second mask; a thirdstep of adjusting a width of a pattern of the second mask; and a fourthstep of etching the target layer using the second mask the width ofwhich is adjusted. The first step includes: measuring the width of thepattern of the first mask for each of a plurality of areas formed in thefirst film; calculating a positive difference value obtained bysubstracting a predetermined reference width from the measured value ofthe width for each of the plurality of areas; adjusting a temperature ofthe target layer for each of the plurality of areas such that a filmhaving a film thickness corresponding to the difference value is formedby using pre-acquired correspondence data indicating correspondencebetween a temperature of the target layer and a film thickness of a filmdeposited on the surface of the mask on the target layer, and thedifference value calculated for each of the plurality of areas; andforming a film having the film thickness of the difference value foreach of the plurality of areas on the surface of the mask of the targetobject by using an atomic layer deposition, after the adjusting. Thethird step includes: measuring the width of the pattern of the secondmask for each of a plurality of areas; calculating a positive differencevalue obtained by subtracting a predetermined reference width from themeasured value of the width for each of the plurality of areas;adjusting a temperature of the target layer for each of the plurality ofareas such that a film having a film thickness corresponding to thedifference value is formed by using pre-acquired correspondence dataindicating correspondence between a temperature of the target layer anda film thickness of a film deposited on the surface of the second maskon the target layer, and the difference value calculated for each of theplurality of areas; and forming a film having the film thickness of thedifference value for each of the plurality of areas on the surface ofthe mask of the target object by using an atomic layer deposition, afterthe adjusting.

As described above, there is provided the method of suppressing avariation in a highly precise critical dimension in forming a pattern onan target object.

Hereinafter, various embodiments will be described in detail withreference to the drawings. Further, in each drawing, the same referencenumeral is given to the same or similar parts.

FIG. 1 is a flowchart illustrating a method for processing a targetobject according to an embodiment. Method MT illustrated in FIG. 1 is anembodiment of a method for processing a target object. FIG. 2 is across-sectional view illustrating a target object (hereinafter, referredto as a wafer W), which is a target of application of method MTillustrated in FIG. 1. A wafer W illustrated in FIG. 2 includes asubstrate BA, a layer to be etched EL2, a layer to be etched EL1, anorganic film OL, an antireflection film AL, and a mask MK.

The layer to be etched EL2 is provided on the substrate BA. The layer tobe etched EL1 is provided on the layer to be etched EL2. The layer to beetched EL1 and the layer to be etched EL2 are layers containing silicon,and for example, amorphous silicon layers or polycrystalline siliconlayers. The organic film OL is a film formed of an organic material andis provided on the layer to be etched EL1. The antireflection film AL isan antireflection film containing Si, and is provided on the organicfilm OL. The mask MK is provided on the antireflection film AL and on amain surface FW of the wafer W. The mask MK is a mask formed of anorganic material, and for example, a resist mask. A pattern providing anopening is formed in the mask MK by photolithography.

Method MT (the method for processing the target object) is executed by aprocessing system including a plasma processing device. FIG. 3 is adiagram illustrating an example of a processing system, which is usablefor carrying out method MT illustrated in FIG. 1. The processing system1 illustrated in FIG. 3 includes a control unit Cnt, a table 122 a, atable 122 b, a table 122 c, and a table 122 d, an accommodatingcontainer 124 a, an accommodating container 124 b, an accommodatingcontainer 124 c, and an accommodating container 124 d, a loader moduleLM, a load lock chamber LL1, a load lock chamber LL2, a transfer chamber121, ad a plasma processing apparatus 10.

The control unit Cnt is a computer including a processor, a storageunit, an input device, and a display device, and controls each unit ofthe processing system 1, which will be described below. The control unitCnt is connected to a transport robot Rb1, a transport robot Rb2, anoptical observation device OC, and the plasma processing apparatus 10.Further, in the plasma processing apparatus 10 illustrated in FIG. 4,which will be described below, the control unit Cnt is connected to avalve group 42, a flow rate controller group 44, an exhaust device 50, afirst high frequency power supply 62, a matcher 66, a second highfrequency power supply 64, a matcher 68, a power supply 70, a heaterpower supply HP, and a chiller unit.

The control unit Cnt is operated according to a computer program (aprogram based on an input recipe) for controlling each unit of theprocessing system 1 in each step of method MT and transmits a controlsignal. Each unit, for example, the transport robots Rb1 and Rb2, theoptical observation device OC, and the plasma processing apparatus 10 ofthe processing system 1 is controlled by the control signal from thecontrol unit Cnt. In the plasma processing apparatus 10 illustrated inFIG. 4, by the control signal from the control unit Cnt, it is possibleto control a selection and a flow rate of gas supplied from the gassource group 40, the exhaust of the exhaust device 50, supply of powerfrom the first high frequency power supply 62 and the second highfrequency power supply 64, application of a voltage from the powersupply 70, supply of power from the heater power supply HP, and acoolant flow rate and a coolant temperature from the chiller unit.Further, each step of method MT for processing the target objectdisclosed in the present specification may be executed by operating eachunit of the processing system 1 under the control of the control unitCnt. In the storage unit of the control unit Cnt, a computer program forexecuting method MT and various data (for example, corresponding data DTto be described below) used for executing method MT are stored to bereadable.

The tables 122 a to 122 d are arranged along an edge of the loadermodule LM. The accommodating containers 124 a to 124 d are provided inthe tables 122 a to 122 d, respectively. The wafers W may beaccommodated in the accommodating containers 124 a to 124 d.

The transport robot Rb1 is provided inside the loader module LM. Thetransport robot Rb1 takes out the wafer W accommodated in any one of theaccommodating containers 124 a to 124 d and transports the wafer W tothe load lock chamber LL1 or LL2.

The load lock chamber LL1 and LL2 are provided along another edge of theloader module LM and connected to the loader module LM. The load lockchambers LL1 and LL2 constitute a preliminary depression chamber. Eachof the load lock chambers LL1 and LL2 is connected to the transferchamber 121.

The transfer chamber 121 is a chamber, which is capable of decompressingpressure, and the transport robot Rb2 is provided inside the transferchamber 121. The plasma processing apparatus 10 is connected to thetransfer chamber 121. The transport robot Rb2 take outs the wafer W fromthe load lock chamber LL1 or the load lock chamber LL2 and transportsthe wafer W to the plasma processing apparatus 10.

The processing system 1 includes the optical observation device OC. Thewafer W may be shifted between the optical observation device OC and theplasma processing apparatus 10 by the transport robot Rb1 and thetransport robot Rb2. The wafer W is accommodated in the opticalobservation device OC by the transport robot Rb1, and after the wafer Wis aligned in the optical observation device OC, the optical observationdevice OC measures a groove width of a pattern of the mask (for example,the mask MK) of the wafer W and transmits a measurement result to thecontrol unit Cnt. In the optical observation device OC, the groove widthof the pattern of the mask may be measured for each of the plurality ofareas ER (to be described below) of the main surface FW.

FIG. 4 is a diagram illustrating an example of the plasma processingdevice, which may include the processing system illustrated in FIG. 3.FIG. 4 schematically illustrates a cross-section structure of the plasmaprocessing apparatus 10 usable in various embodiments of method MT forprocessing the target object.

As illustrated in FIG. 4, the plasma processing apparatus 10 is a plasmaetching device including a parallel flat electrode, and includes theprocessing container 12. The processing container 12 approximately has acylindrical shape and defines a processing space Sp. The processingcontainer 12 is formed of, for example, aluminum, and an inner wallsurface thereof is subjected to an anodizing treatment. The processingcontainer 12 is protected and grounded.

A support part 14 approximately having a cylindrical shape is providedon a bottom of the processing container 12. The support part 14 isformed of, for example, an insulating material. The insulating materialforming the support part 14 may include oxygen, like quartz. The supportpart 14 is extended from the bottom of the processing container 12 in avertical direction within the processing container 12. A mounting tablePD is provided within the processing container 12. The mounting table PDis supported by the support part 14.

The mounting table PD holds the wafer W on an upper surface of themounting table PD. The main surface FW of the wafer W is on the oppositeside of a back surface of the wafer W, which is in contact with theupper surface of the mounting table PD, and faces an upper electrode 30.The mounting table PD includes a lower electrode LE and an electrostaticchuck ESC. The lower electrode LE includes a first plate 18 a and asecond plate 18 b. The first plate 18 a and the second plate 18 b areformed of, for example, metal, such as aluminum, and approximately havea disk shape. The second plate 18 b is provided on the first plate 18 a,and is electrically connected with the first plate 18 a.

The electrostatic chuck ESC is provided on the second plate 18 b. Theelectrostatic chuck ESC has a structure, in which an electrode that is aconductive film is disposed between a pair of insulating layers or apair of insulating sheets. A DC power supply 22 is electricallyconnected to an electrode of the electrostatic chuck ESC through aswitch 23. When the wafer W is disposed on the mounting table PD, thewafer W is in contact with the electrostatic chuck ESC. The back surface(the surface opposite to the main surface FW) of the wafer W is incontact with the electrostatic chuck ESC. The electrostatic chuck ESCadsorbs the wafer W by an electrostatic force such as a Coulomb forcegenerated by a DC voltage from the DC power supply 22. Accordingly, theelectrostatic chuck ESC may hold the wafer W.

A focus ring FR is provided on a peripheral portion of the second plate18 b so as to surround the edge of the wafer W and the electrostaticchuck ESC. The focus ring FR is provided for improving uniformity ofetching. The focus ring FR is formed of a material appropriatelyselected by a material of a film to be etched, and may be formed of, forexample, quartz.

A coolant flow path 24 is provided inside the second plate 18 b. Thecoolant flow path 24 constitutes a temperature control mechanism.Coolant is supplied to the coolant flow path 24 through a pipe 26 a froma chiller unit (not illustrated) provided outside the processingcontainer 12. The coolant supplied to the coolant flow path 24 returnsto the chiller unit through a pipe 26 b. As described above, the coolantis supplied so as to circulate the coolant flow path 24. By controllinga temperature of the coolant, a temperature of the wafer W supported bythe electrostatic chuck ESC may be controlled.

A gas supply line 28 is provided to the plasma processing apparatus 10.The gas supply line 28 supplies a heat transfer gas, for example, He gasfrom a heat transfer gas supply mechanism to a section between an uppersurface of the electrostatic chuck ESC and the back surface of the waferW.

A temperature adjusting unit HT for controlling a temperature of thewafer W is provided in the plasma processing apparatus 10. Thetemperature adjusting unit HT is embedded in the electrostatic chuckESC. The heater power supply HP is connected to the temperatureadjusting unit HT. Power is supplied to the temperature adjusting unitHT from the heater power supply HP, so that a temperature of theelectrostatic chuck ESC is adjusted and a temperature of the wafer Warranged on the electrostatic chuck ESC is adjusted. Further, thetemperature adjusting unit HT may also be embedded in the second plate18 b.

The temperature adjusting unit HT includes a plurality of heatingelements emitting heat, and a plurality of temperature sensors eachconfigured to detect a temperature in the vicinity of the plurality ofheating elements. When the wafer W is aligned on the electrostatic chuckESC, each of the plurality of heating elements is arranged in each ofthe plurality of areas ER (to be described below) of the main surface FWof the wafer W. When the wafer W is aligned and arranged on theelectrostatic chuck ESC, the control unit Cnt recognizes the heatingelement and the temperature sensor corresponding to each of theplurality of areas ER of the main surface FW of the wafer W inassociation with the area ER. The control unit Cnt may distinguish thearea ER, and the heating element and the temperature sensorcorresponding to the area ER by, a number, such as a figure or acharacter, for each of the plurality of areas (for each of the pluralityof areas ER). The control unit Cnt detects a temperature of one area ERby the temperature sensor provided at a position corresponding to theone area ER, and controls a temperature of the one area ER by theheating element provided at the position corresponding to the one areaER. Further, the temperature detected by one temperature sensor when thewafer W is arranged on the electrostatic chuck ESC is the same as atemperature of the area ER on the temperature sensor in the wafer W(more particularly, a temperature of the area ER in a target layer J1which is to be described below).

The plasma processing apparatus 10 includes the upper electrode 30. Theupper electrode 30 is arranged to face the mounting table PD above themounting table PD. The lower electrode LE and the upper electrode 30 areprovided substantially parallel to each other, and constitute a parallelflat electrode. The processing space Sp for performing the plasmaprocessing on the wafer W is provided between the upper electrode 30 andthe lower electrode LE.

The upper electrode 30 is supported on an upper part of the processingcontainer 12 through an insulating shielding member 32. The insulatingshielding member 32 is formed of an insulating material, and mayinclude, for example, oxygen, like quartz. The upper electrode 30 mayinclude an electrode plate 34 and an electrode support body 36. Theelectrode plate 34 faces the processing space Sp, and a plurality of gasdischarge holes 34 a is provided to the electrode plate 34. In anembodiment, the electrode plate 34 contains silicon. In a separateembodiment, the electrode plate 34 may contain a silicon oxide.

The electrode support body 36 supports the electrode plate 34 to bedetachable, and may be formed of a conductive material, for example,aluminum. The electrode support body 36 may have a water coolingstructure. A gas diffusion chamber 36 a is provided inside the electrodesupport body 36. A plurality of gas flow holes 36 b communicating withthe gas discharge holes 34 a is extended downward from the gas diffusionchamber 36 a. A gas inlet 36 c guiding a processing gas to the gasdiffusion chamber 36 a is formed in the electrode support body 36, and agas supply pipe 38 is connected to the gas inlet 36 c.

A gas source group 40 is connected to the gas supply pipe 38 through avalve group 42 and a flow rate controller group 44. The gas source group40 includes a plurality of gas sources. The plurality of gas sources mayinclude a source of organic group-containing aminosilane-based gas, asource of fluorocarbon-based gas (C_(x)F_(y) gas (x and y are integersof 1 to 10) a source of gas having oxygen atoms and carbon atoms (forexample, carbon dioxide gas), a source of nitrogen gas, a source ofhydrogen gas, and a source of noble gas. As the aminosilane-based gas,gas having a molecular structure with a relatively small number of aminogroups may be used, and for example, monoaminosilane (H₃—Si—R (R is anamino group, which may include an organic group and may be substituted)may be used. The aminosilane-based gas (gas included in first gas G1which is to be described below) may include aminosilane, which may haveone to three silicon atoms, or may include aminosilane having one tothree amino groups. The aminosilane having one to three silicon atomsmay be monosilane (monoaminosilane) having one to three amino groups,disilane having one to three amino groups, or trisilane having one tothree amino groups. Further, the aminosilane may have an amino groupwhich may be substituted. Further, the amino group may be substituted byany one of a methyl group, an ethyl group, a propyl group, and a butylgroup. Further, the methyl group, the ethyl group, the propyl group, orthe butyl group may be substituted by halogen. As the fluorocarbon-basedgas, predetermined fluorocarbon-based gas, such as CF₄ gas, C₄F₆ gas,and C₄F₈ gas, may be used. As the noble gas, predetermined noble gas,such as Ar gas and He gas, may be used.

The valve group 42 includes a plurality of valves, and the flow ratecontroller group 44 includes a plurality of flow rate controllers, suchas a mass flow controller. Each of the plurality of gas sources of thegas source group 40 is connected to the gas supply pipe 38 through acorresponding valve of the valve group 42 and a corresponding flow ratecontroller of the flow rate controller group 44. Accordingly, the plasmaprocessing apparatus 10 may supply the gas from the one or more gassources selected from the plurality of gas sources of the gas sourcegroup 40 into the processing container 12 with a separately controlledflow rate.

In the plasma processing apparatus 10, a deposit shield 46 is detachablyprovided along an inner wall of the processing container 12. The depositshield 46 is also provided on an outer periphery of the support part 14.The deposit shield 46 prevents etching by-products (deposits) from beingdeposited in the processing container 12, and may be formed by coatingan aluminum material with ceramics, such as Y₂O₃. The deposit shield maybe formed of a material, for example, quartz, including oxygen, inaddition to Y₂O₃.

An exhaust plate 48 is provided at the bottom side of the processingcontainer 12, that is, a space between the support part 14 and thelateral wall of the processing container 12. The exhaust plate 48 may beformed by coating an aluminum material with ceramics, such as Y₂O₃. Anexhaust port 12 e is provided in the processing container 12 which is alower side of the exhaust plate 48. The exhaust device 50 is connectedto the exhaust port 12 e through an exhaust pipe 52. The exhaust device50 includes a vacuum pump, such as a turbo molecular pump, and maydecompress a space within the processing container 12 to a desiredvacuum level. A loading and unloading port 12 g of the wafer W isprovided on the lateral wall of the processing container 12, and theloading and unloading port 12 g may be opened and closed by a gate valve54.

The plasma processing apparatus 10 further includes the first highfrequency power supply 62 and the second high frequency power supply 64.The first high frequency power supply 62 is a power supply generatingfirst high frequency power for generating plasma, and generates highfrequency power at a frequency of 27 to 100 MHz, for example, 60 MHz.Further, the first high frequency power supply 62 has a pulsespecification, and may be controlled at a frequency of 5 to 10 kHz and aduty of 50 to 100%. The first high frequency power supply 62 isconnected to the upper electrode 30 through the matcher 66. The matcher66 is a circuit for matching output impedance of the first highfrequency power supply 62 and input impedance at a load side (the lowerelectrode (LE) side). Further, the high frequency power supply 62 may beconnected to the lower electrode LE through the matcher 66.

The second high frequency power supply 64 is a power supply forgenerating second high frequency power for drawing ions to the wafer W,that is, high frequency bias power, and generates high frequency biaspower at a frequency within a range of 400 kHz to 40.68 MHz, forexample, a frequency of 13.56 MHz. Further, the second high frequencypower supply 64 has a pulse specification and may be controlled at afrequency of 5 to 40 kHz and a duty of 20 to 100%. The second highfrequency power supply 64 is connected to the lower electrode LE throughthe matcher 68. The matcher 68 is a circuit for matching outputimpedance of the second high frequency power supply 64 and inputimpedance at the load side (the lower electrode (LE) side).

The plasma processing apparatus 10 further includes the power supply 70.The power supply 70 is connected to the upper electrode 30. The powersupply 70 applies a voltage for drawing positive ions present within theprocessing space Sp into the electrode plate 34 to the upper electrode30. In the example, the power supply 70 is a DC power supply generatinga negative DC voltage. When the voltage is applied to the upperelectrode 30 from the power supply 70, the positive ions present in theprocessing space Sp collide with the electrode plate 34. Accordingly,secondary electrons and/or silicon are discharged from the electrodeplate 34.

Method MT will be described hereinafter in detail based on an embodimentcarried out in the processing system 1 including the plasma processingapparatus 10 as an example with reference to FIGS. 1, 5, 8, and 9.Further, method MT may be carried out in a processing system differentfrom the processing system 1, and the processing system may include aplasma processing device, other than the plasma processing apparatus 10.

First, method MT illustrated in FIG. 1 includes steps SA1 to SA4. StepSA1 includes step SA11 (the second step) of etching the antireflectionfilm AL by using the mask MK illustrated in FIG. 2. Step SA2 subsequentto step SA1 includes step SA21 (the second step) of etching the organicfilm OL by using the mask formed of the antireflection film AL by theetching performed in step SA11. Step SA3 subsequent to step SA2 includesstep SA31 of etching the layer to be etched EL1 by using the mask formedof the organic film OL by the etching performed in step SA21, and stepSA32 of removing the mask by ashing the mask formed of the organic filmOL after step SA31. Step SA4 subsequent to step SA3 includes step SA41of etching the layer to be etched EL2 by using the mask formed of thelayer to be etched EL1 by the etching performed in step SA31.

In step SA11, the antireflection film AL is etched. Particularly, aprocessing gas containing fluorocarbon gas is supplied into theprocessing container 12 from the gas source selected from the pluralityof gas sources of the gas source group 40. Further, high-frequency poweris supplied from the first high frequency power supply 62.High-frequency bias power is supplied from the second high frequencypower supply 64. A pressure inside the processing container 12 is set toa predetermined pressure by operating the exhaust device 50. Through theforegoing steps, plasma of the fluorocarbon gas is generated within theprocessing space Sp of the processing container 12. An active speciesincluding fluorine in the generated plasma etches a region exposed fromthe mask MK out of the entire region of the antireflection film A. Bythe etching of the antireflection film AL, the mask used for etching theorganic film OL is formed from the antireflection film AL.

In step SA21, the organic film OL is etched. Particularly, a processinggas containing nitrogen gas and hydrogen gas is supplied to theprocessing container 12 from the gas source selected from the pluralityof gas sources of the gas source group 40. Further, high-frequency poweris supplied from the first high frequency power supply 62. Highfrequency bias power is supplied from the second high frequency powersupply 64. The pressure inside the processing container 12 is set to apredetermined pressure by operating the exhaust device 50. Through theforegoing steps, plasma of the processing gas containing nitrogen gasand hydrogen gas is generated in the processing space Sp of theprocessing container 12. Hydrogen radical, which is an active species ofhydrogen in the generated plasma etches the region exposed from the maskformed of the antireflection film AL in step SA11 out of the entireregion of the organic film OL. By the etching of the organic film OL, amask used for etching the layer to be etched EL1 is formed of theorganic film OL. Further, as gas for etching the organic film OL, aprocessing gas containing oxygen may be used.

Step SA31 of step SA3 subsequent to step SA2, the layer to be etched EL1is etched. Particularly, a processing gas is supplied to the processingcontainer 12 from the gas source selected from the plurality of gassources of the gas source group 40. The processing gas may beappropriately selected depending on a material forming the layer to beetched EL1. For example, the layer to be etched EL1 is formed of asilicon oxide, the processing gas may include fluorocarbon gas. Further,high-frequency power is supplied from the first high frequency powersupply 62. High frequency bias power is supplied from the second highfrequency power supply 64. The pressure inside the processing container12 is set to a predetermined pressure by operating the exhaust device50. Through the steps, plasma is generated. The active species in thegenerated plasma etches the region exposed from the mask formed of theorganic film OL by the etching performed in step SA21 out of the entireregion of the layer to be etched EL1. After step SA31, in step SA32, themask formed of the organic film OL in step SA21 is ashed. Particularly,a processing gas is supplied to the processing container 12 from the gassource selected from the plurality of gas sources of the gas sourcegroup. The processing gas may include oxygen gas and oxygen atoms.Further, high frequency power is supplied from the first high frequencypower supply 62. High frequency bias power is supplied from the secondhigh frequency power supply 64. The pressure inside the processingcontainer 12 is set to a predetermined pressure by operating the exhaustdevice 50. Through the steps, plasma is generated. The active species inthe generated plasma ashes the mask formed of the organic film OL instep SA21. Further, as gas for ashing the mask formed of the organicfilm OL in step SA21, a processing gas containing nitrogen gas andhydrogen gas may be used.

In step SA41 of step SA4 subsequent to step SA3, the layer to be etchedEL2 is etched. Particularly, a processing gas is supplied to theprocessing container 12 from the gas source selected from the pluralityof gas sources of the gas source group 40. The processing gas may beappropriately selected depending on a material forming the layer to beetched EL2. For example, when the layer to be etched EL2 is formed ofamorphous silicon, the processing gas may include halogen-based gas.Further, high frequency power is supplied from the first high frequencypower supply 62. High frequency bias power is supplied from the secondhigh frequency power supply 64. The pressure inside the processingcontainer 12 is set to a predetermined pressure by operating the exhaustdevice 50. Through the steps, plasma is generated. The active species inthe generated plasma etches the region exposed from the mask formed ofthe layer to be etched EL1 by the etching and ashing performed in stepsSA31 and SA32 out of the entire region of the layer to be etched EL2.

Steps SA1, SA2, SA3, and SA4 may include step SAA (the first step) ofadjusting a groove width of the pattern before the etching. In step SAA,before the etching, a groove width of the pattern of the mask used inthe etching is adjusted. When step SAA is performed in step SA1, stepSAA is performed before step SA11. When step SAA is performed in stepSA2, step SAA is performed before step SA21. When step SAA is performedin step SA3, step SAA is performed before step SA31. When step SAA isperformed in step SA4, step SAA is performed before step SA41.

A state of a wafer W, which is a processing target of step SAA (that is,a processing target of the step illustrated in FIG. 5 to be describedbelow) is illustrated in FIG. 6A. FIG. 6B is a cross-sectional viewillustrating a state of the wafer W before the step illustrated in FIG.5 (step SAA) is performed. The wafer W illustrated in FIG. 6A includes atarget layer J1 and a mask J2. The mask J2 is provided on a main surfaceJ11 of the target layer J1 (when the mask J2 corresponds to a mask MK,the main surface J11 corresponds to a main surface FW of the wafer W).

When step SAA illustrated in FIG. 1 is executed in step SA1 of etchingthe antireflection film AL, the target layer J1 is the antireflectionfilm AL and the mask J2 is the mask MK. In step SA11, after step SAA isexecuted, the target layer J1 is etched by using the mask, on which theprocessing of adjusting the groove width is performed.

When step SAA illustrated in FIG. 1 is executed in step SA2 of etchingthe organic film OL, the target layer J1 is the organic film OL, and themask J2 is the mask formed of the antireflection film AL by the etchingperformed in step SA11. In step SA21, after step SAA is executed, thetarget layer J1 is etched by using the mask, on which the processing ofadjusting the groove width is performed.

When step SAA illustrated in FIG. 1 is executed in step SA3 of etchingthe layer to be etched EL1, the target layer J1 is the layer to beetched EL1, and the mask J2 is the mask formed of the organic film OL bythe etching performed in step SA21. In step SA31, after step SAA isexecuted, the target layer J1 is etched by using the mask, on which theprocessing of adjusting the groove width is performed.

When step SAA illustrated in FIG. 1 is executed in step SA4 of etchingthe layer to be etched EL2, the target layer J1 is the layer to beetched EL2, and the mask J2 is the mask formed of the layer to be etchedEL1 by the etching and the ashing performed in steps SA31 and SA32. Instep SA41, after step SAA is executed, the target layer J1 is etched byusing the mask, on which the processing of adjusting the groove width isperformed.

Next, step SAA illustrated in FIG. 1 will be described in detail withreference to FIG. 5. FIG. 5 is a flowchart illustrating an example ofthe step of adjusting a groove width of a pattern before etching, whichis a step (step SAA) may be included in the method illustrated in FIG.1.

In step SAA (in the processing performed by the control unit Cnt), themain surface J11 of the target layer J1 of the wafer W is divided intothe plurality of areas ER. FIG. 7 is a diagram schematicallyillustrating some of a plurality of divided areas ER of the main surfaceof the target layer J1 of the wafer W in method MT according to anembodiment as an example. The plurality of areas ER does not overlap.The main surface J11 of the target layer J1 (the main surface FW of thewafer W) is coated with the plurality of areas ER. A shape of the areaER is, for example, a shape of an area concentrically extended based ona center point of the main surface J11 (a center point of the mainsurface FW) of the target layer J1, or an area in a lattice shape, butis not limited thereto.

As illustrated in FIG. 5, step SAA includes steps SB1 to SB7, and stepsSB5 to SB7 may be executed a plurality of times (repeatedly) accordingto determination results of steps SB3 and SB4. First, in step SB1 (thethird step), a value of a groove width of the pattern of the mask J2 ismeasured for each of the plurality of areas ER of the main surface J11of the target layer J1 by the optical observation device OC of theprocessing system 1.

In step SB2 (the fourth step) subsequent to step SB1, a positivedifference value obtained by subtracting a reference value of the groovewidth from the value of the groove width of the pattern of the mask J2measured in step SB1 is calculated for each of the plurality of areas ERof the main surface J11 of the target layer J1.

In step SB3 subsequent to step SB2, it is determined whether theadjustment of the groove width of the pattern has been already onceperformed (the case where the adjustment of the groove width of thepattern has been already once performed is the case where the adjustmentof the groove width of the pattern has been already once performed insteps SB5 to SB7, which will be described below), and when theadjustment of the groove width of the pattern has not been performed yet(when the adjustment of the groove width of the pattern is initiallyperformed) (step SB3: No), the process proceeds to step SB5. In stepSB3, when the adjustment of the groove width of the pattern has beenalready once performed (step SB3: Yes), the process proceeds to stepSB4.

In step SB4, it is determined whether it is necessary to re-adjust thegroove width of the pattern based on the difference value of the groovewidth of the pattern calculated in step SB2. In step SB4, when it isnecessary to re-adjust the groove width of the pattern (step SB4: Yes),steps SB5 to SB7 are re-executed. That is, steps SB1 and SB2 arere-executed after steps SB5 to SB7 are executed, and when the differencevalue calculated in step SB2 does not satisfy a predetermined referencerange due to the re-execution (step SB4: Yes), steps SB5 to SB7 arere-executed. The reference range is a range including the referencevalue of the groove width used in step SB2. In step SB4, when it is notnecessary to re-adjust the groove width of the pattern (step SB4: No),that is, when the difference value calculated in step SB2 satisfies thepredetermined reference range, the processing of step SAA is terminated.

In step SB5 subsequent to step SB3 (Yes) and step SB4 (Yes), the wafer Wis shifted to the plasma processing apparatus 10 from the opticalobservation device OC by the transport robot Rb1 and the transport robotRb2 and the wafer W is loaded into the processing container 12 of theplasma processing apparatus 10.

In step SB6 (the fifth step) subsequent to step SB5, a film J3 having afilm thickness of the difference value of each of the plurality of areasER calculated in step SB2 (a film in which a film thickness of each ofthe plurality of areas ER is the difference value calculated in step SB2for each of the plurality of areas ER) is formed on a surface J21 of themask J2 of the wafer W loaded into the processing container 12. The filmJ3 is a silicon oxide film. FIG. 6B is a cross-sectional viewillustrating a state of the wafer W before the step illustrated in FIG.5 (step SB6) is performed. In the wafer W illustrated in FIG. 6B, thefilm J3 is formed on the surface J21 of the mask J2. Further, thecontents of the processing performed in step SB6 will be described indetail below.

In step SB7 subsequent to step SB6, the wafer W is shifted to theoptical observation device OC from the plasma processing apparatus 10 bythe transport robot Rb1 and the transport robot Rb2 and the wafer W isloaded into the optical observation device OC. After step SB7, stepsSB1, SB2, and SB3 are re-executed.

Step SB6 will be described in detail with reference to FIGS. 8 and 9.FIG. 8 is a flowchart illustrating an example of the step of adjustingthe groove width of the pattern, which is a part of the stepsillustrated in FIG. 5 (step SB6). FIG. 9 is a flowchart illustrating anexample of a step of forming a uniform film on the main surface J11 ofthe target layer J1, which is a step (step SCC) that may be included inthe steps illustrated in FIG. 8.

As illustrated in FIG. 8, step SB6 includes steps SC1 to SC9. Steps SC5to SC8 form sequence SQ1. Sequence SQ1 and step SC9 are film formingprocessing for forming the film J3 on the surface J21 of the mask J2 ofthe wafer W. Steps SC1 to SC4 are preparation processing required forexecuting the film forming processing constituted by sequence SQ1 andstep SC9.

In step SC1, the wafer W loaded into the processing container 12 of theplasma processing apparatus 10 is aligned and provided on theelectrostatic chuck ESC. In step SC2 subsequent to step SC1, similar tostep SB3, it is determined whether the adjustment of the groove width ofthe pattern has been already once performed (the case where theadjustment of the groove width of the pattern has been already onceperformed is the case where the adjustment of the groove width of thepattern has been already once performed in steps SB5 to SB7, which is tobe described below), and when the adjustment of the groove width of thepattern has not been performed yet (when the adjustment of the groovewidth of the pattern is initially performed) (step SC2: No), the processproceeds to step SC3. Further, the determination result of step SC2corresponds to the determination result of step SB3 illustrated in FIG.5. Further, there is a case where step SC3 is not executed when step SAAincluding step SC3 is performed in step SA2 of etching the organic film(step SAA is performed after step SA1 and before step SA21).

In step SC2, when the adjustment of the groove width of the pattern hasbeen already once performed (step SC2: Yes), the process proceeds tostep SC4 or step SCC (the twelfth step). Further, since thedetermination result of step SC2 is the same as the determination resultof step SB3, the determination processing of step SC2 may be performedby referring to the determination result of step SB3.

In step SCC, the film is conformally formed on the surface J21 of themask J2 regardless of the plurality of areas ER. Step SCC will bedescribed in detail with reference to FIG. 9 below. Further, asillustrated in FIG. 8, step SB6 may be the configuration, which does notinclude step SCC, but when step SB6 includes step SCC, step SCC may beexecuted between step SC3 or step SC2 (No) and step SC4 (that is, beforestep SC4) or after step SC9 (Yes) (that is, after the film formingprocessing), which is to be described below.

Step SC3 subsequent to step SC2 (Yes), secondary electrons are emittedto the wafer W. Step SC3 is an step of emitting the secondary electronsto the mask J2 by generating plasma within the processing space Sp ofthe processing container 12 and applying a negative DC voltage to theupper electrode 30 before sequence SQ1 and step SC9 of forming the filmJ3 on the surface J21 of the mask J2 are executed.

As described above, before the series of processes of sequence SQ1 tostep SC9 of forming the film J3 on the surface J21 of the mask J2 areexecuted, the secondary electrons are emitted to the mask J2, so that itis possible to reform the mask J2 before the film J3 is formed, therebysuppressing damage to the mask J2 due to the subsequent steps.

The contents of the processing of step SC3 will be described in detail.First, hydrogen gas and noble gas are supplied into the processingcontainer 12, and high-frequency power is supplied from the first highfrequency power supply 62, so that plasma is generated within theprocessing space Sp. Hydrogen gas and noble gas are supplied into theprocessing container 12 from the gas source selected from the pluralityof gas sources of the gas source group 40. Accordingly, positive ions inthe processing space Sp are drawn into the upper electrode 30, so thatthe positive ions collide with the upper electrode 30. The positive ionscollide with the upper electrode 30, so that the secondary electrons aredischarged from the upper electrode 30. The discharged secondaryelectrons are emitted to the wafer W, so that the mask J2 is reformed.Further, the positive ions collide with the electrode plate 34, so thatsilicon, which is the material forming the electrode plate 34, isdischarged together with the secondary electrons. The discharged siliconis combined with oxygen discharged from the configuration component ofthe plasma processing apparatus 10 exposed to plasma. The oxygen isdischarged from the member, for example, the support part 14, theinsulating shielding member 32, and the deposit shield 46. A siliconoxide compound is generated by a combination of silicon and oxygen, andthe silicon oxide compound is deposited on the wafer W and covers andprotects the mask J2. As described above, in step SC3 of emitting thesecondary electrons to the mask J2, the negative DC voltage is appliedto the upper electrode 30 by generating plasma within the processingspace Sp, so that the secondary electrons are emitted to the mask J2 andsimultaneously silicon is discharged from the electrode plate 34 tocover the mask J2 with the silicon oxide compound including the silicon.Further, the secondary electrons are emitted to the mask J2, the mask J2is covered with the silicon oxide compound, and then the inside of theprocessing container 12 is purged, and the process proceeds to step SC4or step SCC. As described above, when the silicon oxide compound coversthe mask J2 in step SC3, it is possible to further suppress damage tothe mask J2 due to the subsequent steps.

Further, in step SC3, in order to reform the mask or form the protectionfilm by the emission of the secondary electrons in step SC3, thedischarge of silicon may be suppressed by minimizing the bias power ofthe second high frequency power supply 64. Further, in method MT, stepSC3 may be excluded.

After step SC3 or step SC2 (No), the process proceeds to step SC4 (thetenth step) by going through step SCC or without going through step SCC.In step SC4, for each of the plurality of areas ER of the main surfaceJ11 of the target layer J1 of the wafer W, a temperature of the targetlayer J1 of the wafer W is adjusted by using a temperature adjustingunit HT. In step SC4, the temperature of the target layer J1 is adjustedfor each of the plurality of areas ER by using pre-acquiredcorrespondence data DT indicating correspondence between the temperatureof the target layer J1 and a film thickness of a film deposited on thesurface J21 of the mask J2 on the target layer J1 (a film formed by thefilm forming processing (sequence SQ1 and step SC9), which will bedescribed below), and the film thickness corresponding to the differencevalue calculated for each of the plurality of areas ER in step SB2. Thecorrespondence data DT is pre-acquired data by depositing the film J3 onthe surface J21 of the mask J2 based on the same condition as that ofthe film forming processing constituted by sequence SQ1 and step SC9(the condition in which the temperature of the target layer J1 isexcluded) for each temperature of the target layer J1, and is stored tobe readable in the storage unit of the control unit Cnt.

In step SC4, when step SB6 does not include step SCC, the temperature ofthe target layer J1 is adjusted based on the correspondence data DT foreach of the plurality of areas ER so that the temperature of each of theplurality of areas ER in the target layer J1 of the wafer W loaded intothe processing container 12 becomes the temperature corresponding to thefilm thickness of the difference value calculated for each of theplurality of areas ER in step SB2.

In step SC4, when step SB6 includes step SCC, that is, step SCC isperformed before step SC4, after step SC3, or after step SC2 (No), orstep SCC is performed after the film forming processing constituted bystep SQ1 and step SC9, the temperature of the target layer J1 isadjusted based on the correspondence data DT for each of the pluralityof areas ER so that the temperature of each of the plurality of areas ERin the target layer J1 of the wafer W loaded into the processingcontainer 12 becomes the temperature corresponding to the value obtainedby subtracting a film thickness of the conformally formed film in stepSCC from the film thickness of the difference value calculated for eachof the plurality of areas ER in step SB2.

In the film forming processing (the eleventh step) constituted by stepSQ1 and step SC9 subsequent to step SC4, the film (the film J3 or a partof the film J3 when step SCC is executed in step SB6) is formed on thesurface J21 of the mask J2 on the target layer J1 of the wafer W loadedinto the processing container 12. The film forming processingconstituted by step SQ1 and step SC9 is the step of conformally formingthe silicon oxide film on the surface J21 of the mask J2 of the wafer Wwith a uniform thickness for each of the plurality of areas ER by thesame method as the atomic layer deposition (ALD) method. During theexecution of step SC5 of sequence SQ1, the temperature of the targetlayer J1 of the wafer W adjusted for each of the plurality of areas ERin step SC4 is maintained. Because of this, the film formed by the filmforming processing may have a different film thickness for each of theplurality of areas ER, but after the film J3 including the film formedby the film forming processing is formed on the surface J21 of the maskJ2 (step SB4: No) and after step SAA, the groove width of the mask J2has a desired value (the reference value of the groove width for each ofthe plurality of areas ER used for calculating the difference value instep SB2).

The film forming processing (sequence SQ1 and step SC9) will bedescribed in detail. Sequence SQ1 includes steps SC5 to SC8. In step SC5(the sixth step), first gas G1 is supplied into the processing container12. Particularly, in step SC5, as illustrated in FIG. 10A, the first gasG1 containing silicon is introduced into the processing container 12.The first gas G1 includes organic contained aminosilane-based gas. Thefirst gas G1 is aminosilane-based gas, and gas having a molecularstructure with a relatively small number of amino groups may be used asthe first gas G1, and for example, monoaminosilane (H₃—Si—R (R is anamino group, which may include an organic group and may be substituted)may be used. Further, the aminosilane-based gas used as the first gas G1may include aminosilane, which may have one to three silicon atoms, ormay include aminosilane having one to three amino groups. Theaminosilane having one to three silicon atoms may be monosilane(monoaminosilane) having one to three amino groups, disilane having oneto three amino groups, or trisilane having one to three amino groups.Further, the aminosilane may have an amino group which may besubstituted. Further, the amino group may be substituted by any one of amethyl group, an ethyl group, a propyl group, and a butyl group.Further, the methyl group, the ethyl group, the propyl group, or thebutyl group may be substituted by halogen. The first gas G1 of theorganic group-containing aminosilane-based gas is supplied into theprocessing container 12 from the gas source selected from the pluralityof gas sources of the gas source group 40. In step SC5, plasma of thefirst gas G1 is not generated.

A processing time required in step SC5 is within a time, in which thefilm thickness of the film deposited on the surface J21 of the mask J2on the target layer J1 is in an increasing/decreasing state according toa high/low temperature of the target layer J1 in step SC5. Theprocessing time may be a time shorter than a processing time (aprocessing time during which the film having the film thickness may beformed on the surface J21 of the mask J2 on the target layer J1regardless of the temperature of the target layer J1), corresponding toa self-limited region in the ALD method.

Molecules of the first gas G1 are attached to the main surface J11 ofthe target layer J1 (particularly, the surface J21 of the mask J2 on themain surface J11) as a reaction precursor (a layer Ly1) as illustratedin FIG. 10B. The molecules of the first gas G1 are attached to thesurface J21 of the mask J2 by chemical adsorption based on a chemicalcombination, and plasma is not used. Further, as the first gas, gas G1,which is attachable to the surface J21 of the mask J2 by a chemicalcombination based on the temperature of the target layer J1 adjusted foreach of the plurality of areas ER in step SC4 and also contains silicon,may be used.

In the meantime, for example, in the case where monoaminosilane isselected as the first gas G1, monoaminosilane is selected becausemonoaminosilane has relatively high electro negativity and chemicaladsorption may be relatively easily performed due to a molecularstructure having polarity. The layer Ly1 of the reaction precursorformed by the attachment of the molecules of the first gas G1 to thesurface J21 of the mask J2 becomes a state close to a monomolecularlayer (single layer) because the attachment is the chemical adsorption.As the amino group R of the monoaminosilane is smaller, the molecularstructure of the molecule adsorbed to the surface J21 of the mask J2becomes smaller, so that steric inhibition caused by a size of themolecule is reduced, and thus the molecules of the first gas G1 may beuniformly adsorbed to the surface J21 of the mask J2 for each of theplurality of areas ER and the layer Ly1 may be formed with the uniformfilm thickness for each of the plurality of areas ER for the surface J21of the mask J2.

As described above, since the first gas G1 includes the organicgroup-containing aminosilane-based gas, the reaction precursor (thelayer Ly1) of silicon is formed on the mask J2 along an atomic layer ofthe surface J21 of the mask J2 by step SC5.

In step SC6 (the seventh step) subsequent to step SC5, the inside of theprocessing container 12 is purged. Particularly, the first gas G1supplied in step SC5 is exhausted. In step SC6, inert gas, such asnitrogen gas or noble gas (for example, Ar) may be supplied into theprocessing container 12 as purge gas. That is, the purge of step SC6 maybe any one of gas purge, in which inert gas flows into the processingcontainer 12 or purge by a vacuum state. In step SC6, the moleculesexcessively attached to the surface J21 of the mask J2 may be removed.By the steps, the layer Ly1 of the reaction precursor becomes a verythin monomolecular layer.

In step SC7 (the eighth step) subsequent to step SC6, as illustrated inFIG. 10B, plasma P1 of second gas is generated in the processing spaceSp of the processing container 12. The second gas includes gascontaining oxygen atoms and carbon atoms, and may include, for example,carbon dioxide gas. In step SC7, a temperature of the target layer J1 ofthe wafer W when the plasma P1 of the second gas is generated may be,for example, 0° C. or higher and 200° C. or lower. The second gasincluding a gas containing oxygen atoms and carbon atoms is suppliedinto the processing container 12 from the gas source selected from theplurality of gas sources of the gas source group 40. Further,high-frequency power is supplied from the first high frequency powersupply 62. In this case, bias poser of the second high frequency powersupply 64 may be applied, and plasma may also be generated only with thesecond high frequency power supply 64. A pressure of the space withinthe processing container 12 is set to a predetermined pressure bysupplying high frequency bias power from the second high frequency powersupply 64 and operating the exhaust device 50. As described above, theplasma P1 of the second gas is generated within the processing space Sp.

As illustrated in FIG. 10B, when the plasma P1 of the second gas isgenerated, active species of oxygen and active species of carbon, forexample, oxygen radical and carbon radical, are generated, and asillustrated in FIG. 10C, a layer Ly2 (layer included in the film J3),which is a silicon oxide layer, is formed as a monomolecular layer.Since the carbon radical may exert a function of suppressing the mask J2from being oxygen eroded, the silicon oxide film may be stably formed onthe surface J21 of the mask J2 as a protection layer. Binding energy ofSi—O bond of the silicon oxide layer is about 192 kcal, and is higherthan binding energy (about 50 to 110 kcal, about 70 to 110 kcal, and 100to 120 kcal) of C—C bond, C—H bond, and C—F bond, which are several bondspecies of the organic film forming the mask, so that the silicon oxidefilm may exert a function as the protection film.

As described above, since the second gas includes oxygen atoms, in stepSC7, the oxygen atoms are bound to the reaction precursor (the layerLy1) of silicon arranged on the mask J2, so that the layer Ly2 of thesilicon oxide layer may be conformally formed with a different filmthickness for each of the plurality of areas ER on the mask J2. Further,since the second gas includes carbon atoms, the erosion of the mask J2due to the oxygen atoms may be suppressed by the carbon atoms.Accordingly, in sequence SQ1, by the same method as the ALD method, thelayer Ly2 of the silicon oxide film may be conformally formed on thesurface J21 of the mask J2 for each of the plurality of areas ER withthe uniform film thickness according to the temperature of each of theplurality of areas ER.

In step SC8 (the ninth step) subsequent to step SC7, the inside of theprocessing container 12 is purged. Particularly, the second gas suppliedin step SC7 is exhausted. In step SC8, inert gas, such as nitrogen gasor noble gas (for example, Ar) may be supplied into the processingcontainer 12 as purge gas. That is, the purge of step SC8 may be any oneof gas purge, in which inert gas flows into the processing container 12or purge by a vacuum state.

In step SC9 subsequent to sequence SQ1, it is determined whether thenumber of times of the repetition of sequence SQ1 reaches apredetermined number of times (for example, 50 times), and when it isdetermined that the number of times of the repetition of sequence SQ1does not reach the predetermined number of times (step SC9: No),sequence SQ1 is executed again, and when it is determined that thenumber of times of the repetition of sequence SQ1 reaches thepredetermined number of times (step SC9: Yes), step SB6 is terminated.That is, in step SC9, by repeatedly executing sequence SQ1 until thenumber of times of the repetition of sequence SQ1 reaches thepredetermined number of times, the film having the film thicknessaccording to a temperature of each of the plurality of areas ER isformed on the surface J21 of the mask J2 for each of the plurality ofareas. The number of times of the repetition of sequence SQ1 controlledby step SC9 is determined according to the processing time of step SC5and the film thickness of the film (the film J3, or a part of the filmJ3 when step SCC is executed in step SB6) formed by the film formingprocessing constituted by sequence SQ1 and step SC9.

Herein, step SCC will be described in detail with reference to FIG. 9.Step SCC constituted by sequence SQ2 and step SD5. Sequence SQ2constituted by steps SD1 to SD4. Step SD1 of sequence SQ2 corresponds tostep SC5 of sequence SQ1 illustrated in FIG. 8, but step SD1 isdifferent from step SC5 in that a temperature of the target layer J1 instep SD1 is different from the temperature of the target layer J1 instep SC5, and the processing time required in step SD1 is different froma processing time required in step SC5. In steps SD2 to SD4 of sequenceSQ2, the same processing as that of steps SC6 to SC8 of sequence SQ1illustrated in FIG. 8 is performed, respectively.

The number of times of the repetition of sequence SQ2 controlled by stepSD5 is determined according to the film thickness of the film (the partof the film J3) formed by step SCC. The film J3 formed in step SB6 isformed of the film formed in step SCC and the film formed by the filmforming processing (sequence SQ1 and step SC9). The film thickness ofthe film J3 formed in step SB6 is a sum value of the film thickness ofthe film formed in step SCC and the film thickness of the film formed bythe film forming processing (sequence SQ1 and step SC9).

A processing time in step SD1 of sequence SQ2 is a processing timecorresponding to a self-limited region (the processing time, in whichthe film having the film thickness may be formed on the surface J21 ofthe mask J2 on the target layer J1 regardless of the temperature of thetarget layer J1) in the ALD method, and is longer than the processingtime of step SC5 of sequence SQ1. In step SD1, a temperature of thetarget layer J1 of the wafer W may be, for example, 0° C. or higher and200° C. or longer.

A particular example of a method of writing the correspondence data DTaccording to an embodiment will be described. The correspondence data DTindicates correspondence between the temperature of the target layer J1and the film thickness of the film (the film formed by the film formingprocessing (sequence SQ1 and step SC9) deposited on the surface J21 ofthe mask J2 on the target layer J1, and is data pre-acquired before theexecution of method MT by depositing the film J3 on the surface 21 ofthe mask J2 based on the same condition (the condition, in which thetemperature of the target layer J1 is executed) as that of the filmforming processing constituted by sequence SQ1 and step SC9 for eachtemperature of the target layer J1.

First, for each of the plurality of temperatures (hereinafter, a valueof the temperature is referred to as “KR”) of the target layer J1, arelation (hereinafter, the relation is referred to as “F1” with afunction of the processing time TM and the temperature KR) between theprocessing time in step SC5 (hereinafter, a value of the processing timeis referred to as “TM”) and the film thickness (hereinafter, a value ofthe film thickness is referred to as “VL”) formed by the film formingprocessing is measured. For each of the temperatures KR, a relation VL(VL=F1(TM; KR)) of the processing time TM and the film thickness VL maybe preferably approximated by the logarithm functionVL=α1(KR)×1n(TM)+β1(KR) (Equation 1). α1(KR) is a constant determinedfor each KR, 1n(TM) is a natural logarithm for TM, and β1(KR) is aconstant determined for each KR. In Equation 1 (approximate expression),the film thickness VL of the film formed by the film forming processingis larger as when the temperature KR is higher as can be seen from theequation (Arrhenius plot) of Arrhenius for the temperature KR, but inthe self-limited region of the ALD method, the film thickness VL of thefilm formed by the film forming processing converges to a nearlyconstant value, regardless of KR.

α1(KR) and β1(KR) included in Equation 1 may be approximated asdescribed below. A reciprocal (1/α1(KR)) of α1(KR) may be preferablyapproximated by a first function, 1/α1(KR)=α2×KR+β2 (Equation 2). α2 andβ2 are constants determined at the time of the calculation of Equation 2(approximate expression). β1(KR) may be preferably approximated by alogarithm function, β1(KR)=α3×1n(KR)+β3 (Equation 3) as a function ofKR. α3 and β3 are constants determined at the time of the calculation ofEquation 3 (approximate expression). 1n(KR) is a natural logarithm forKR.

Equations 2 and 3 are applied to α1(KR) and β1(KR) included in Equation1, respectively, so that Equation 1 is expressed byVL=1n(TM)/(α2×KR+β2)+α3×1n(KR)+β3 (Equation 4). That is, the filmthickness VL may be uniquely calculated according to the temperature KRwhen the processing time TM is fixed with a constant value (theprocessing time required in step SC, which is shorter than theprocessing time corresponding to the self-limited region in the ALDmethod and the processing time, in which the film thickness VL issufficiently changed by the temperature KR). As described above, thecorrespondence data DT may be written by Equation 4. Further, thecorrespondence data DT may also be written by a method, other than themethod using Equations 1 to 4.

In method MT according to the embodiment, before step SA11 (or stepSA21, step SA31, and step SA41) of etching the target layer J1, step SAAof adjusting the groove width of the pattern of the mask J2 isperformed. In step SAA, the main surface J11 of the target layer J1 isdivided into the plurality of areas ER, a difference value between thegroove width of the mask J2 and the reference value of the groove widthis calculated for each of the plurality of areas ER in steps SB1 andSB2, and the film J3 having the film thickness corresponding to thedifference value is formed on the mask J2 in step SB6 to correct thegroove width of the mask to the reference value for each of theplurality of areas ER. In step SB6, the film is very precisely formed onthe mask J2 for every atom layer by the same method as the ALD method byusing the film forming processing, in which steps SC5 to SC8 arerepeatedly executed. The film thickness of the film formed by the filmforming processing is different according to a temperature of the targetlayer J1, so that in step SC4, the temperature of the target layer J1 isadjusted so as to be the temperature required for forming the filmhaving the film thickness corresponding to the difference valuecalculated in step SB2 for each of the plurality of areas ER by usingthe corresponding data DT indicating the correspondence between thetemperature of the target layer J1 and the film thickness of the formedfilm. As described above, before the etching performed in step SA11 (orstep SA21, step SA31, and step SA41), a film thickness corresponding toa correction amount of the groove of the mask J2 is determined for eachof the plurality of areas ER of the main surface J11 of the target layerJ1, a temperature of the target layer J1 required for forming the filmthickness is determined by using the correspondence data DT, and thesame film forming processing as the ALD method is performed in the statewhere the temperature of the target layer J1 is adjusted to thetemperature determined for each of the plurality of areas ER, so thatthe variation of the pattern of the mask J2 may be precisely andsufficiently suppressed for each of the plurality of areas ER of themain surface J11 of the target layer J1.

Further, when step SCC of conformally forming the film on the surfaceJ21 of the mask J2 regardless of the plurality of areas ER is used inmethod MT, for the common film thickness among the film thicknesses ofthe plural areas ER, it is possible to partially form the film by stepSCC without adjusting the temperature of the target layer J1 performedon each of the plurality of areas ER in step SC4.

Further, after the film J3 is formed in step SB6, a difference value ofthe groove width of the mask J2 is calculated again and it is determinedwhether the difference value is within the reference range (steps SB1 toSB4), and when the difference value is not within the reference range,it is necessary to form the film J3 again, so that the variation of thegroove width of the mask J2 may be more sufficiently suppressed.

In the foregoing, the embodiment has been described with the principleof the present disclosure, but those skilled in the art recognizes thatthe present disclosure may be changed in disposition and details withoutdeparting from the principle. The present disclosure is not limited tothe specific configurations disclosed in the present embodiment.Accordingly, all modifications and changes in the claims and the scopeof the spirit of the claims are claimed.

What is claimed is:
 1. A substrate processing system comprising: asubstrate processing apparatus including a processing chamber, asubstrate support, and a temperature controller configured to adjusts atemperature of the substrate support; an optical monitor; and acontroller configured to cause: (a) providing the substrate having atarget layer and a pattern on the target layer; (b) measuring a width ofthe pattern by the optical monitor; (c) calculating a difference betweenthe width of the pattern and a reference value; (d) controlling thetemperature controller to adjust the temperature of the substratesupport to a temperature at which a film having a thicknesscorresponding to the difference between the width of the pattern and thereference value is formed at least on a sidewall of the pattern based ona relationship between a film formation temperature and a film formationamount; (e) forming a film on the pattern to have a thicknesscorresponding to the difference between the width of the pattern and thereference value at least on the sidewall of the pattern; and (f) etchingthe target layer using the pattern on which the film is formed.
 2. Thesubstrate processing system according to claim 1, wherein the targetlayer includes a plurality of areas, and the temperature controllerincludes: a heater configured to generate heat for each of the pluralityof areas of the target layer; and a temperature sensor configured todetect a temperature around the heater.
 3. The substrate processingsystem according to claim 1, wherein the target layer includes aplurality of areas, and the controller performs (c) to (e) for each ofthe plurality of areas of the target layer.
 4. The substrate processingsystem according to claim 1, wherein the substrate support includes anelectrostatic chuck, and the temperature controller is embedded in theelectrostatic chuck.
 5. The substrate processing system according toclaim 1, further comprising a transfer chamber, a load-lock chamber, anda loader module connected to each other, wherein the optical monitor isdisposed adjacent to the loader module, and the substrate is transferredbetween the optical monitor and the processing chamber via the transferchamber, the load-lock chamber and the loader module.
 6. The substrateprocessing system according to claim 1, wherein the substrate processingapparatus is a plasma etching apparatus including a parallel flatelectrode.
 7. The substrate processing system according to claim 1,wherein the pattern is formed as an opening in a mask of the targetlayer.
 8. The substrate processing system according to claim 1, whereinthe relationship between a film formation temperature and a filmformation amount is obtained by performing a film formation in advanceunder the same condition as that of (e) with respect to a temperature ofthe target layer.
 9. The substrate processing system according to claim1, wherein, in (e), the film is formed by an ALD method.
 10. Thesubstrate processing system according to claim 1, wherein (e) includes:(e1) exposing the pattern to a first processing gas to form a reactionprecursor; and (e2) exposing the reaction precursor to a plasmagenerated from a second processing gas to form the film.
 11. Thesubstrate processing system according to claim 9, wherein (e) furtherincludes: (e3) repeating (e1) and (e2).
 12. A method comprising: (a)providing a substrate having a target layer and a pattern on the targetlayer to a substrate support; (b) measuring a width of the pattern by anoptical monitor; (c) calculating a difference between the width of thepattern and a reference value; (d) adjusting a temperature of thesubstrate support to a temperature at which a film having a thicknesscorresponding to the difference between the width of the pattern and thereference value is formed at least on a sidewall of the pattern based ona relationship between a film formation temperature and a film formationamount; (e) forming a film on the pattern to have a thicknesscorresponding to the difference between the width of the pattern and thereference value at least on the sidewall of the pattern; and (f) etchingthe target layer using the pattern on which the film is formed.
 13. Themethod according to claim 12, wherein the target layer includes aplurality of areas, and (c) to (e) are performed for each of theplurality of areas of the target layer.
 14. The method according toclaim 12, wherein the pattern is an opening formed on a mask of thetarget layer.
 15. The method according to claim 12, wherein therelationship between a film formation temperature and a film formationamount is obtained by performing a film formation in advance under thesame condition as that of the (e) with respect to a temperature of thetarget layer.
 16. The method according to claim 12, wherein, in (e), thefilm is formed by an ALD method.
 17. The method according to claim 12,wherein (e) includes: (e1) exposing the pattern to a first processinggas to form a reaction precursor; and (e2) exposing the reactionprecursor to a plasma generated from a second processing gas to form thefilm.
 18. The method according to claim 17, wherein (e) furtherincludes: (e3) repeating (e1) and (e2).
 19. An apparatus for processinga substrate having a target layer and a pattern on the target layer, theapparatus comprising: a chamber; a substrate support disposed in thechamber; a temperature controller configured to adjusts a temperature ofthe substrate support; and a controller configured to cause: (a) placingthe substrate on the substrate support; (b) receiving a width of thepattern measured by an optical monitor; (c) calculating a differencebetween the width of the pattern and a reference value; (d) controllingthe temperature controller to adjust the temperature of the substratesupport to a temperature at which a film having a thicknesscorresponding to the difference between the width of the pattern and thereference value is formed at least on a sidewall of the pattern based ona relationship between a film formation temperature and a film formationamount; (e) forming a film on the pattern to have a thicknesscorresponding to the difference between the width of the pattern and thereference value at least on the sidewall of the pattern; and (f) etchingthe target layer using the pattern on which the film is formed.